✪ Alekshop 4.6L S65 Stroker - World's Highest HP NA Motor

[Alekshop]

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Alekshop 4.6L S65 Stroker Build:

Many of you have followed our US Spec M3 GTS built.

Now that engine is completed and was put through 4,000 of track and street driving miles it's time to share the results. As many of you already know BMW GTS M3 came with 4.4L Stroker motor. We decided to build our US Spec GTS M3 with even higher displacement and decided to go with 4.6L Stroker
motor. We were considering to go with Dinan's or RD Sport 4.6L storker motor for our build but decided to start from the scratch and build our own 4.6L stroker. A great friend of mine "regular guy" helped us with this project and his experience with the stroker engine builds made things much easier. Also we wanted to ensure our motor is built using only the highest grade components and we reached out to Mahle and Carrillo to get our pistons, wrist pins, and rods made. The crankshaft was also custom made with slightly larger rod journal clearance designed in. The pistons and wrist pins were custom made by Mahle @ 93.0 mm bore. Carrillo provided custom made connecting rods of custom length and pin bore sizes. A local shop helped us with the assembly of the motor.

After looking at some stroker dyno's with our friend "regular guy" we though it would be beneficial to add mild cams to our motor. We've heard lots of people talking about adding cams to S65, but nobody seems to have followed through all the way through tuning and posting their results. So I think that makes us first to be able to run S65 with cams. We chose the mild Schrick 284-degree cams because they allow us to keep VANOS, whereas the higher duration Schrick cams do not.

Now that the engine was build, we decided to take the car to ESS Tuning in Arizona and have AJ tune it on their dyno. We spent 4 days playing with different files, driving the car letting it to adapt and making changes as needed. it was a fun process and guy at ESS did an excellent job!

The last part was to find out if and how much power this new motor is making. Dyno wizard with "regular guy" came to the rescue again!

We took our US Spec M3 GTS to three different dyno's for testing. We ran both 94 octane, and standard California 91 octane. The 91 octane dyno's were run at the same facility as our baseline dyno before the motor swap. For the 94 octane dyno's, we decided to take our car to EAS in Anaheim, and Specialty-Z
in Canoga Park California as many of the guys on the forums are using these places for their dyno runs and we thought it would be a decent comparison to other NA M3s. We dyno'd at both facilities on the
same day, same gasoline, only hours apart. For anybody
curious, both dyno's gave the same exact results (3-5hp apart) and even showed the same power band bumps and dips in the same exact locations. To
us, these dyno's were identical to each other.

From all the research online and going through S65 dyno database, we haven't found a street car that made more power than our 4.6L Stroker and we decided to claim to have the first World's Highest HP Street NA Motor


























Car and
Modifications:

• 2013 BMW M3 GTS US Spec
• Akekshop 4.6L Stroker Engine
• Schrick 284-degree Cams
• Akrapovic GT4 Exhaust
• Both CAT Delete
• ESS ECU Tune
• 94 Octane
• 91 Octane,
• DCT GTS Software

Conditions (Dynojet Weather
Station):



Results:



Dyno Database:

• Dyno files are available from the links below.
• 94 Octane:
  SAE
  Corrected,
  STD
  Corrected,
  Uncorrected
• 91 Octane:
  SAE
  Corrected,
  STD
  Corrected,
  Uncorrected

Individual Dyno
Results:

Individual dyno results are shown below. SAE corrected results are
shown twice, using two different sources. The first source (djc)
are the SAE corrected results straight from the Dynojet. The
second source (sae) of SAE corrected results are obtained by using
the Kestral 4500 weather station data for each individual dyno run
and running it through an independent SAE correction formula. This
ensures that the dyno results are accurate and can be
independently audited and verified for authenticity and accuracy.

The legend below has the following meaning:

• Dyno Run: Dyno run file
• Timestamp
• Temp(F) = Temperature (Farenheit)
• RelH = Relative Humidity
• Pressure(Hg) = Barometric Pressure
• DA(ft) = Density Altitude
• WHP(unc) = Uncorrected wheel horsepower
• WTQ(unc) = Uncorrected wheel torque
• WHP(SAEd) = Dynojet SAE corrected wheel horsepower (SAE-1340
  PRE-2004)
• WTQ(SAEd) = Dynojet corrected wheel torque (SAE-1349 PRE-2004)
• WHP(SAEk) = SAE-Adapted wheel horsepower (SAE-1349 2004+)
• WTQ(SAEk) = SAE-Adapted wheel torque (SAE-1349 2004+)

94 Octane:



91 Octane:


* Entry used for the Dyno Database

Graphs:
SAE Correction (94 Octane):


SAE Correction (91 Octane):


STD Correction (94 Octane):


STD Correction (91 Octane):


Uncorrected (94 Octane):


Uncorrected (91 Octane):


Engine Vital Statistics (91
Octane):


Comparison:

• Alekshop 4.0L Full Bolt-On (91 Octane)
• Dinan 4.6L Stroker (91 Octane)
• RD Sport 4.6L Stroker (91 Octane)
• Alekshop 4.6L Stroker (91 Octane)

Gains with Cams (91 Octane):
Many people want to know how the cams worked out. The previous
stroker builds all showed us that the strokers fall flat after
about 7000 RPMs. I wanted to add cams to help fix this problem.
Cams will give up torque on the bottom end and move it up top. But
how much do we give up on the bottom, and how much do we gain on
the top? Will the gains on the top be worth the sacrifice on the
bottom? We think so.

All of the strokers show very strong torque, usually about 75
ft/lbs over stock motors. So it should be worth giving up a little
of this torque to smooth out and fix the top end gains.

Our tests showed undeniable results. The cams gave up about 20
ft/lbs on the bottom, but gained the same exact amount on the top.
In the process, we picked up 24 horsepower over the non-cammed
stroker, and as the chart below shows, the cams really smoothed
out the power curves up top. There is no doubt, the stroker motor
needed cams to make it breath and perform better.



Thanks for reading!

Aleks.

[BrewRifle]

Awesome work. What engine oil are you folks running in it?

[Disturbed]

I am not sure I want to ask but...what's a 4.6 build cost?

I have no doubts it is more than a SC kit...but would like to know anyway.

[BrewRifle]

Originally Posted by Disturbed

I am not sure I want to ask but...what's a 4.6 build cost?

I have no doubts it is more than a SC kit...but would like to know anyway.

I'm guessing around 26k, based off of Dinan's build.

[Shredicus]

Great pics and great build! Nice work guys

[MFL]

Hump!

[Alekshop]

Originally Posted by BrewRifle

Awesome work. What engine oil are you folks running in it?

Thanks!

Been running Motul 300V 10W40.

[Alekshop]

Originally Posted by Disturbed

I am not sure I want to ask but...what's a 4.6 build cost?

I have no doubts it is more than a SC kit...but would like to know anyway.

The price is determined by the parts your want to use to build it. Dinan uses A-beam rods which a lower quality. We went with H-beam which a higher quality.

But yes, it will cost more than a SC kit.

[W///]

This art. Wow

[ilikebmxbikes]

Looks very good. I just got a Dinan 4.6L and will be protuning it with Mike Benvo. I hope to achieve similar numbers.

[backhill]

Great results!

Just to be clear, this is the highest HP NA S65 motor in the world and not just in general.

[Alekshop]

Originally Posted by backhill

Great results!

Just to be clear, this is the highest HP NA S65 motor in the world and not just in general.

yup

we haven't seen any higher dyno numbers on the street naturally aspirated S65 motor

[Alekshop]

Originally Posted by ilikebmxbikes

Looks very good. I just got a Dinan 4.6L and will be protuning it with Mike Benvo. I hope to achieve similar numbers.

That's great Marco! Hopefully it can be tuned to that!

[IMG]

Very impressive !
Received your oil cooler btw, can't wait to get it installed. Thx

[Alekshop]

Originally Posted by IMG

Very impressive !
Received your oil cooler btw, can't wait to get it installed. Thx

Great!

Your LC build is up next ?

[warp10]

Nice work Aleks

[OM VT3]

How does it sound with the cams?

[Alekshop]

Originally Posted by leigh

How does it sound with the cams?

Sounds awesome

I'll post a video from the dyno day in a bit.

[dereksM3]

Your guys threads are absolutely some of the best and most informative on this site. I always look forward to reading them. This one in particular really is what I had hoped for. I still wish a fully decked out 4.6L would make more WHP on 94oct but it's not bad none the less. I really look forward to hearing it!

[Alekshop]

Originally Posted by dereksM3

Your guys threads are absolutely some of the best and most informative on this site. I always look forward to reading them. This one in particular really is what I had hoped for. I still wish a fully decked out 4.6L would make more WHP on 94oct but it's not bad none the less. I really look forward to hearing it!

Thanks!

There are ways to make more power but we may explore it on the next 4.6L build.

Aleks.

[DLSJ5]

Great work Aleks!

[Rupes]

Very cool, congrats!